>There is no requirement for landlords to register substantial rehabilitation work to HCR, according to Josephson, who said notifications to the agency are in effect a voluntary process adhered to by property owners in only “a small minority of the cases.”

>HCR could, in theory, question why buildings that have previously registered rent-stabilized units suddenly do not, Josephson added — but the state agency “doesn’t really have the capacity to check every apartment that disappears off the rolls,” he said

They aren't actually fixing the units. And there's no system to make sure they did and aren't lying. And is hazard to guess almost all of them are lying. That's the issue.